1. Field of the Invention
This invention relates to vehicles and more particularly to a power wheel chair having an improved motion control.
2. Description of the Related Art
Attendant operated patient transport vehicles may be characterized as either a manual wheelchair type or a powerchair personal mobility vehicle type with a joystick attendant control. Each of these transport vehicles has certain advantages and disadvantages.
A conventional manual wheelchair was not originally designed or intended to be pushed by an attendant or a caregiver. The handles for pushing a conventional manual wheelchair are poorly designed from an ergonomic standpoint for pushing by an attendant or a caregiver. Many attendants and caregivers incur back, neck, leg and carpal tunnel injuries from pushing a conventional manual wheelchair. Since many of the caregivers are spouses of an elderly disabled person, the spouses are at higher risk for heart attacks and accidental falls that can cause serious injury to both the attendant and wheelchair occupant.
The manual brakes of a conventional manual wheelchair are located on the front of the manual wheelchair and designed as parking brakes. Frequently, the attendant/caregiver fails to engage the parking brakes of a conventional manual wheelchair when the occupant is getting on or off of the conventional manual wheelchair that leads to further injuries. Furthermore, since the parking brakes are located on the front of the manual wheelchair, an attendant cannot engage the parking brakes while the wheelchair is in motion such as descending a ramp.
A powerchair personal mobility vehicle typically comprises a short frame having plural drive wheels and plural casters or idler wheels. The plural drive may be either front or the rear drive wheels with the caster or idler wheels providing the stability for the powerchair. The plural drive wheels are independently driven by plural electric motors. The plural electric motors are independently controlled by a control for independently driving the plural electric motors.
A joystick operates the control for controlling both the turning, speed, direction and braking of the powerchair. The turning of the powerchair is accomplished by a differential in speed between the plural independently driven electric motors. The control also enables one of the plural electric motors to have a reverse rotation relative to the other of the plural electric motors. The powerchair personal mobility vehicle is well suited for confined areas such as inside use due to the short frame and the superior turning radius of the plural independently driven electric motors. The short wheelbase provides a reduced turning radius for the personal mobility vehicle for negotiating smaller confined spaces indoors.
A scooter type personal mobility vehicle has been available for use by an occupant. A scooter personal mobility vehicle typically comprises an elongated frame having front wheel and plural rear wheels. The front wheel is pivotably mounted on the front portion of the elongated frame. A tiller and handlebar is provided for pivoting the front wheel for steering the personal mobility vehicle. The plural rear wheels are mounted on a common shaft driven by a single electric motor. The electric motor is controlled by a variable speed control and a forward and reverse located on the handlebar of the scooter. The scooter type personal mobility vehicle is well suited for unconfined areas such as outside use due to the superior ride of the elongated wheelbase of the scooter. The elongated wheelbase provides more stability and a better ride for the scooter personal mobility vehicle.
Typically, the cost of a powerchair personal mobility vehicle is greater than the cost of a scooter personal mobility vehicle due to the cost of plural electric motors in addition to the increased cost of a joystick operated dual-motor differential control relative to the single motor speed control of the scooter personal mobility vehicle.
Some powerchairs of the prior art were available with an optional primary or secondary joystick control for enabling an attendant or a caregiver to operate the powerchair from behind the seat of the powerchair. Unfortunately, it is difficult to operate a joystick of a powerchair vehicle while walking behind the seat of the powerchair. Because of the cost of a secondary joystick and the difficulty in operating the joystick control of the powerchair from behind the seat, the use of these optional attendant joysticks have not find widespread use in the art.
It is an object of the present invention to provide a power wheel chair that overcomes the inadequacies of the prior art vehicles and provides significant advancement in the patient transport art.
Another object of this invention is to provide a power wheel chair with maneuverability commensurate with a powerchair.
Another object of this invention is to provide a power wheel chair at cost significantly less than a powerchair.
Another object of this invention is to provide a power wheel chair with an improved motion control.
Another object of this invention is to provide a power wheel chair with an improved motion control that does not substantially increase the weight of the power wheel chair.
Another object of this invention is to provide a power wheel chair with an improved motion control that is easier to use while walking behind the powered vehicle.
Another object of this invention is to provide a power wheel chair with an improved motion control that is easier to use while walking along a side of the powered vehicle.
The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed as being merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be obtained by modifying the invention within the scope of the invention. Accordingly other objects in a full understanding of the invention may be had by referring to the summary of the invention, the detailed description describing the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.